Wire set having a sheath bonded to a polyvinylchloride overmolding using polyurethane

ABSTRACT

An electrical apparatus according to the present disclosure comprises a molded device having a molded portion and being formed via an overmolding process. The electrical apparatus includes a wire set at least partially overmolded within the device, the wire set having an outer sheath surrounding a plurality of wires. The molded portion surrounds a portion of the wire set. The electrical apparatus further includes polyurethane bonding material occurring between the outer sheath and the molded portion. The polyurethane bonding material bonds at least a portion of the wire set to the molded portion during the overmolding process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/689,061, filed Jan. 18, 2010 now U.S. Pat. No. 8,226,872, which ishereby incorporated by reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to overmolding an electrical circuit, andmore particularly to a system and method for polyurethane bonding duringand/or after overmolding of the circuit.

BACKGROUND OF THE DISCLOSURE

It is well known to form molded items through use of a die moldassembly. Often times, the molded items encapsulate components viaplacement of the components in the die mold cavity prior to overmolding.In some cases, it may also be desirable to provide for or otherwiseenhance the bonding of components encapsulated within the molded item.In the past, various types of glues have been used as bonding agentsduring the overmolding process, such as cyanoacrylate-based glues as anexample. However, such glues have been shown to cause brittleness orotherwise degrade the material on which they are applied. Additionally,solvents such as acetone and cyclohexanone, as examples, have been usedto clean the component to be overmolded in an attempt to enhance thebonding affect. However, such solvents are often hazardous to the user'shealth and the environment and are required to be applied immediatelyprior to the overmolding process to ensure that the solvents do not loseeffectiveness through handling of the components and other activities.Other techniques such as sand blasting the component prior toovermolding have been attempted, however such techniques also requireapplication immediately prior to the overmolding process to ensureeffectiveness.

There is therefore a need for a system and method to improve in anovermolded item. The present disclosure is directed toward systems andmethods which meet this and other needs.

SUMMARY OF THE DISCLOSURE

In certain embodiments, a molded item may be prepared by a processcomprising providing a wire set including an outer sheath surrounding aplurality of wires, the outer sheath having an outer surface. Theprocess includes applying a polyurethane bonding material to at least aportion of the outer surface of the outer sheath and positioning atleast a portion of the wire set with polyurethane bonding materialwithin a mold cavity of a molding die. The process further includesovermolding the portion of the wire set within the molding die to formthe molded item, wherein the overmolding includes filling the moldcavity with molten material configured to harden into overmold. Themolten material produces an amount of heat and the heat operates toactivate the polyurethane bonding material to bond the wire set with theovermold within the molded item.

In other embodiments, a method comprises providing a wire harness havinga wire jacket surrounding at least one wire, the wire jacket having anouter surface. The method includes applying a polyurethane bondingmaterial to at least a portion of the outer surface of the wire jacketand positioning at least a portion of the wire harness with polyurethanebonding material applied thereon within a mold cavity of a molding die.The method further includes overmolding the portion of the wire harnesswithin the molding die to form a molded item and activating thepolyurethane bonding material to bond the wire jacket within the moldeditem.

In yet other embodiments, an electrical apparatus comprises a moldeddevice having a molded portion and being formed via an overmoldingprocess. The electrical apparatus includes a wire set at least partiallyovermolded within the device, the wire set having an outer sheathsurrounding a plurality of wires. The molded portion surrounds a portionof the wire set. Additionally, the electrical apparatus includespolyurethane bonding material occurring between the outer sheath and themolded portion. The polyurethane bonding material bonds at least aportion of the wire set to the molded portion during the overmoldingprocess.

In even other embodiments, a method comprises providing a wire setincluding an outer sheath surrounding a plurality of wires, the outersheath having an outer surface. The method includes positioning at leasta portion of the wire set within a mold cavity of a molding die andovermolding the portion of the wire set within the molding die to formthe molded item. The molded item has a front surface with at least onehole extending in from the front surface or at least one prong extendingout from the front surface, the molded item having a back surfaceopposite the front surface with a portion of the wire set extending outfrom the back surface. The overmolding includes filling the mold cavitywith molten material configured to harden into overmold. Additionally,the method includes applying a polyurethane bonding material at thejunction between the molded item and the portion of the wire setextending out from the back surface. The polyurethane bonding materialis applied to the back surface of the molded item and the outer surfaceof the outer sheath to bond the molded item and the wire set.

In further embodiments, a method comprises providing a wire setincluding an outer sheath surrounding a plurality of wires andpositioning at least a portion of the wire set within a mold cavity of amolding die. The method includes overmolding the portion of the wire setwithin the molding die to form the molded item having an outer surface.The overmolding includes filling the mold cavity with molten materialconfigured to harden into overmold. Additionally, the method includesapplying a polyurethane bonding material to the outer surface of theouter sheath to patch a portion of the molded item.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a molded socket according to anembodiment of the present disclosure.

FIG. 2 is a perspective, partial cut-away view of a molded socketaccording to an embodiment of the present disclosure.

FIG. 3 is a cross-sectional view taken along section line 3-3 in FIG. 2.

FIG. 4 is a perspective view of a die mold assembly according to anembodiment of the present disclosure.

FIG. 5 is a perspective view of a wire set engaged with a die moldassembly according to an embodiment of the present disclosure.

FIG. 6 is a perspective view of a molded socket according to anotherembodiment of the present disclosure.

FIG. 7 is a perspective view of a molded socket according to yet anotherembodiment of the present disclosure.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the purposes of promoting an understanding of the principles of thedisclosure, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of thedisclosure is thereby intended, and alterations and modifications in theillustrated systems, and further applications of the principles of thedisclosure as illustrated therein are herein contemplated as wouldnormally occur to one skilled in the art to which the disclosurerelates.

In certain embodiments, the present disclosure is directed to a systemwhich provides for polyurethane bonding of a component within a finishedmolded item during overmolding of the component (see FIGS. 1-5). Thepolyurethane material may be applied to the component in a variety ofpossible ways, as will be discussed in greater detail below, to providea flexible seal between the component and the remainder of the moldeditem. The component having the polyurethane material applied thereto maybe an electrical circuit molded within a die mold cavity to form amolded plug or socket device.

In certain other embodiments, the present disclosure is directed to asystem which provides for polyurethane bonding of a component within afinished molded item after overmolding of the component and/or patchingof the finished molded item after overmolding (see FIGS. 6-7). As anexample, the polyurethane bonding material may be applied to thejunction between the molded item and the unmolded component extendingout from the molded item. The component may be an electrical circuitmolded within a die mold cavity to form a molded plug or socket device.

Referring to FIGS. 1-3, there is shown an example molded socket 10having an electrical circuit molded within the socket, with polyurethanebonding material used during the overmolding process. As bestillustrated in FIG. 2, in certain embodiments the electrical circuit maybe in the form of a wire harness or wire set 12 having a plurality ofwires 14 surrounded by a wire jacket or cable or outer sheath 16. Insome embodiments, the outer sheath 16 may be composed of polyvinylchloride for example; however, it should be appreciated that variousother appropriate materials may be used as would occur to one ofordinary skill in the art. The final molded socket 10 includes anovermolded portion 18 which has been overmolded around a portion of thewire set 12. Additionally, the molded socket 10 includes a front surface20 and a plurality of slots or holes 22 defined in and extending inwardfrom the front surface 20 at least partially into the molded socket 10.The holes 22 may be configured and arranged to receive electricalconnectors, such as corresponding prongs of an electrical plug, in amanner as would occur to one of ordinary skill in the art. In the finalmolded socket 10, the wires 14 extend to the corresponding holes 20 suchthat they are operably connected to form the electrical socket.

In the illustrated embodiment, there are seven wires 14 provided in thewire set 12. However, it is contemplated that there may be more or lesswires within wire set 12 as would occur to one skilled in the art.Additionally, in certain embodiments, the number of holes 22 parallelsthe number of wires 14 within wire set 12. Accordingly, in theillustrated embodiment, there are seven holes 22 corresponding to theseven wires 14. It should be appreciated that wire set 12 can beotherwise configured as would occur to one of ordinary skill in the art,with only one of the numerous possible examples being illustrated.Additionally, it should be appreciated that the representations in theaccompanying figures are for illustrative purposes and are not intendedto be detailed drawings showing all the components of a wire set and/ora molded socket. Additionally, the components which are shown arerepresented in simplified form for ease of understanding.

The molded socket 10 includes polyurethane bonding material 30 appliedto the outer sheath 16 of wire set 12 prior to the overmolding process.The polyurethane material 30 may be operable to bond the wire set 12with the overmolded portion 18 of the molded socket 10 during theovermolding process. In certain embodiments, the polyurethane material30 creates a flexible seal between the wire set 12 and the moldedportion 18 within the socket 10. The polyurethane material 30 may beoperable to inhibit the intrusion of moisture into the socket 10 bypreventing separation of the wire set 12 from the remainder of thesocket 10.

The polyurethane material 30 used in accordance with present disclosuremay be supplied in a variety of different forms as would occur to one ofordinary skill in the art. As in the illustrated embodiment, thepolyurethane material 30 may be placed in the form of a film that isapplied to the outer sheath 16 of the wire set 12. In some embodiments,the film of polyurethane material 30 may be wrapped around thecircumference of the outer sheath 16 along at least one section of thesheath. Polyurethane film material may be made into various shapes andsizes as desired and depending on the size of the wire set and the finalmolded socket. In certain embodiments, a piece of polyurethane filmhaving the desired dimensions may be cut from a roll of polyurethanefilm using known cutting techniques. The size, shape and configurationof the piece of polyurethane film material 30 shown in the accompanyingfigures may be altered as desired and is for illustration purposes only.Additionally, it should be appreciated that the piece of polyurethanefilm material 30 may be wrapped only partially around the circumferenceof the outer sheath 16 or may be wrapped multiple times.

In other embodiments, the polyurethane material may be sprayed on to theouter sheath 16 through a variety of appropriate spray techniques aswould occur to one of ordinary skill in the art. An appropriate sprayingtechnique may allow for consistent and optimal application of thepolyurethane material. In yet other embodiments, the polyurethanematerial may be brushed on to the outer sheath 16. Using a brush toapply a more liquidized form of polyurethane material may provide theuser with the ability to apply the polyurethane material to the outersheath 16 in irregular shapes and/or to evenly apply the polyurethanematerial to irregular surface segments along the outer sheath 16. Ineven other embodiments, an at least partially liquidized form of thepolyurethane material may be applied via a dropper dispenser or similardevice. It should be appreciated that the polyurethane material may beformed and applied prior to the overmolding process in a variety ofother appropriate manners as would occur to one of ordinary skill in theart. Additionally, the polyurethane bonding material may be applied tothe outer sheath 16 at one or multiple locations along the other sheaththat will be subject to the overmolding process and thus will becomepart of the finished molded item. In certain embodiments, thepolyurethane bonding material may be colored as desired.

In certain embodiments, the polyurethane bonding material 30 applied tothe outer sheath 16 may be handled by a user as necessary to perform theremaining steps of the method without substantially affecting thebonding effect of the material. Additionally, the use of polyurethanebonding material 30 may not substantially affect the physical propertiesof the material to which the polyurethane is applied, such as outersheath 16. In alternative embodiments, the present disclosurecontemplates the use or incorporation of other appropriate bondingmaterials having the same or similar properties to polyurethane to serveas the bonding material within the molded item, including otherappropriate and similar polymeric materials.

To form the molded socket 10, a die mold which is arranged andconfigured to form the molded socket may be used. The die mold assembly40 illustrated in FIGS. 4 and 5 is one non-limiting example of a diemold assembly which may be used to create the molded socket 10. Asshown, die mold assembly 40 includes an upper mold component 42 and alower mold component 44 configured to encase a portion of the wire set12 to create the molded socket 10. In the particular illustratedembodiment, an optional slideable plate 52 is engaged with the lowermold component 44. The plate 52 is configured to slide with respect tolower mold component 44 to position the wire set 12 in the optimalposition for the overmolding process. In alternative embodiments, theplate 52 may be integral with and non-moveable with respect to the lowermold component 44. The illustrated slideable plate 52 carries a socketpiece 48 having a plurality of pins 50. As shown in FIG. 2, each of thewires 14 may include a sleeve 60 positioned at the end thereof to engagea pin 50. In such embodiments, the sleeves 60 may slide onto the pins 50to ensure the proper positioning of the ends of the wires 14 adjacentthe pins 50, as shown in FIG. 5.

As illustrated, the lower mold component 44 may include a channel 46defined therein configured to at least partially receive the wire set12. Additionally, the upper and lower mold components 42 and 44 may beconfigured to fit together to enclose a portion of the wire set 12within channel 46. In certain embodiments, the upper and lower moldcomponents 42 and 44 may include a plurality of aligned holes configuredto receive fasteners, such as bolts 70 for example, to secure the moldcomponents together for the overmolding process. It should beappreciated that the mold components may be secured together in avariety of other appropriate ways as would occur to one of ordinaryskill in the art. In alternative embodiments, the mold components mayremain positioned against each other for the overmolding process withoutthe use of fasteners or other securing means. It should be appreciatedthat the die mold assembly 40 shown in FIGS. 4 and 5 is for illustrationpurposes only and is not critical to the present disclosure. It iscontemplated that the die mold assembly used in accordance with thepresent method may be configured and arranged in a variety of differentmanners as would occur to one of ordinary skill in the art.

A particular example method of polyurethane bonding during anovermolding process will now be discussed with reference to FIGS. 1through 5. In certain embodiments, a plurality of wires 14 may bearranged together within an outer sheath 16. Additionally, sleeves 60may be attached to the ends of the wires 14 to allow for connection topins 50 in the mold assembly 40. The polyurethane bonding material 30may be applied to the outer sheath 16 in a variety of appropriatemanners, a few of which are mentioned above. In the particularillustrated embodiment, of a piece of polyurethane film is wrappedaround the outer sheath 16. The polyurethane bonding material 30 isapplied to the outer sheath 16 along at least one section of the sheath16 which will be positioned in the mold assembly 40 to ensure that thepolyurethane bonding material 30 becomes part of the molded item.

The wire set 12 is positioned in the mold assembly 40 either before orafter application of the polyurethane bonding material 30. In theparticular illustrated embodiment, the sleeves 60 on the ends of thewires 14 are placed on the pins 50 of the socket piece 48, as shown inFIG. 5. In optional embodiments in which slideable plate 52 is present,once the connection between wire set 12 and socket piece 48 occurs, theplate 52 may be moved downward with respect to lower mold component 44such that the wire set 12 is resting in the channel 46. The die moldcomponents are used to form a molded item, such as the illustratedsocket 10, via an overmolding process.

Upon proper positioning of the components within the die mold cavity,the components are then overmolded to create a molded item. In certainembodiments, the upper and lower die mold components 42 and 44,respectively, are brought together and a molten plastic material isinjected into the die mold cavity according to a typical moldingprocess. In certain embodiments, a polyvinylchloride material isinjected into the die mold cavity, creating a molded item such as socket10 composed of polyvinylchloride. However, it is contemplated that othermaterials and/or compositions thereof may be used as desired in creatingmolded socket 10. As shown in FIG. 2, the die mold forms the moldedsocket 10 with wire set 12 extending into molded socket 10 and thepolyurethane material 30 bonding the wire set 12 with the interior ofthe socket 10 as a result of the molding process.

In certain embodiments, the heat from the molten plastic materialinjected into the die mold cavity activates the polyurethane material 30and causes it to form a flexible seal or bond between the wire set 12and the interior of the socket 10. In the particular illustratedembodiment, the outer sheath 16 is bonded with the overmolded portion 18of the socket 10 via the polyurethane material 30. In other embodiments,an external heat source may be used to externally activate thepolyurethane bonding material 30. The mechanism used to externallyprovide heat to polyurethane material 30 may be one of a variety ofappropriate mechanisms as would occur to one of ordinary skill in theart. Following the overmolding process, the upper and lower die moldcomponents, such as components 42 and 44, may be separated and themolded item, such as socket 10, may be removed from the die moldassembly 40.

In addition to the application of polyurethane bonding material prior toand/or during the overmolding process as discussed above, in otherembodiments polyurethane bonding material may be applied after theovermolding process to enhance bonding and/or patch areas of the moldeditem. Referring to FIGS. 6-7, there is shown an example molded item 110,such as an electrical socket or plug as examples, having an electricalcircuit molded within the item and with polyurethane bonding materialapplied after the overmolding process is completed. As illustrated, theelectrical circuit may be in the form of a wire harness or wire set 112having a plurality of wires surrounded by a wire jacket or cable orouter sheath 116. The final molded item 110 includes an overmoldedportion 118 which has been overmolded around a portion of the wire set112. In some embodiments, the overmolded portion 118 and/or the outersheath 16 may be composed of polyvinyl chloride for example; however, itshould be appreciated that various other appropriate materials may beused as would occur to one of ordinary skill in the art.

The molded item 110 may be formed using an appropriate die mold, such asdie mold assembly 40 illustrated in FIG. 4. The molded item 110 issimilar in design and configuration to molded socket 10 discussed aboveand therefore much of that discussion will not be repeated for the sakeof brevity. Additionally, it should be appreciated that therepresentations in the figures are for illustrative purposes and are notintended to be detailed drawings showing all the components of a wireset and/or a molded item. Further, the components which are shown arerepresented in simplified form for ease of understanding.

The illustrated overmolded portion 118 includes an outer cylindricalsurface 118 a, a front surface 118 b and an opposite back surface 118 c.As illustrated, a portion of wire set 112 extends out from back surface118 c. In embodiments in which the molded item 110 is an electricalsocket, the item includes at least one hole extending in from the frontsurface 118 b in communication with at least one wire in the wire set112. In other embodiments in which the molded item 110 is an electricalplug, the item includes a plurality of prongs extending out from thefront surface 118 b, with the wires in the wire set 112 forming part ofthe prongs.

In the particular embodiment illustrated in FIG. 6, the molded item 110includes polyurethane bonding material 30 applied at the junctionbetween overmolded portion 118 and the outer sheath 116 after theovermolding process. As shown, a portion of material 30 is applied toback surface 118 c and a portion is applied to the outer sheath 116extending out from back surface 118 c. The polyurethane material 30 maybe operable to enhance the bonding between the wire set 112 and theovermolded portion 118 following the overmolding process. In certainembodiments, the polyurethane material 30 creates a flexible sealbetween the wire set 112 and the molded portion 118 at the juncturetherebetween. The polyurethane material 30 may also be operable toinhibit the intrusion of moisture into the item 110.

In the particular embodiment illustrated in FIG. 7, polyurethane bondingmaterial 30 is applied to a portion of the cylindrical outer surface 118a of portion 118. In certain situations, it may be desirable to apply apatching mechanism to the overmolded portion 118 following theovermolding process. In this way, the polyurethane bonding material 30may be used as a patching mechanism for the portion 118 as needed.

As discussed above, material 30 may be supplied and applied in a varietyof appropriate manners, including the use of a thin polyurethane film,spraying or brushing on a more liquidized form of the polyurethanematerial, or using a dropper dispenser or similar device to apply thepolyurethane material, to name a few non-limiting examples. In theembodiments illustrated in FIGS. 6 and 7, a piece of polyurethane filmis applied to the desired components. In certain embodiments, thepolyurethane bonding material 30 applied after the overmolding processis complete, such as in FIGS. 6 and 7, may be allowed to dry or cure atambient conditions without the application of heat. In otherembodiments, a heat source may be used to activate the polyurethanebonding material 30.

It should be appreciated that although the present disclosure discussesthe formation of a molded socket 10 and a molded item 110, it iscontemplated that numerous types of molded items can be formed viaincorporating the polyurethane bonding material, with the molded socket10 and molded item 110 being non-limiting examples only. As anotherexample, the polyurethane bonding material may be used during theformation of a molded plug, such as a molded plug configured toelectrically connect with the molded socket 10. In addition to thenumerous other final molded items contemplated by the presentdisclosure, it is contemplated that a variety of other appropriatecomponents, electrical or otherwise, may be molded within the finalmolded item. It is contemplated that the polyurethane bonding materialmay be used to assist in bonding items together as part of numeroustypes of overmolding processes.

While the disclosure has been illustrated and described in detail in thedrawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the disclosureare desired to be protected.

What is claimed is:
 1. An electrical apparatus, comprising: a wire sethaving an outer sheath composed of polyvinylchloride surrounding atleast a portion of a plurality of wires; and an overmolded portion beingformed via an overmolding process, wherein the overmolded portionsurrounds at least a portion of the wire set and is composed ofpolyvinylchloride; polyurethane bonding material disposed between theovermolded portion and the outer sheath, wherein the polyurethanebonding material is configured to bond at least a portion of thepolyvinylchloride outer sheath to the polyvinylchloride overmoldedportion.
 2. The apparatus of claim 1, wherein the apparatus is a moldedsocket having a front surface and at least one hole extending from thefront surface at least partially through the socket, wherein at leastone of the plurality of wires extends into the at least one hole in thesocket.
 3. The apparatus of claim 1, wherein the outer sheath issubstantially cylindrical in shape and has a circumference, and whereinthe polyurethane bonding material is a piece of polyurethane filmpositioned around the circumference of the outer sheath along asubstantially cylindrical portion of the outer sheath.
 4. The apparatusof claim 1, wherein the overmolded portion has a front surface and anopposite back surface, with a portion of the wire set extending out fromthe back surface.
 5. An electrical apparatus, comprising: a wire sethaving an outer sheath surrounding at least a portion of a plurality ofwires; and an overmolded portion being formed via an overmoldingprocess, wherein the overmolded portion surrounds at least a portion ofthe wire set; polyurethane bonding material contacting both the outersheath and the overmolded portion, wherein the polyurethane bondingmaterial is configured to bond at least a portion of the wire set to theovermolded portion.
 6. The apparatus of claim 5, wherein the overmoldedportion has a front surface and an opposite back surface, wherein thewire set extends out from the back surface, wherein the polyurethanebonding material is positioned in contact with the outer sheath of thewire set and the back surface of the overmolded portion to bond at leasta portion of the wire set to the overmolded portion following theovermolding process.
 7. The apparatus of claim 5, wherein the overmoldedportion has a front surface and an opposite back surface, wherein thewire set extends out from the back surface, wherein the overmoldedportion defines an adjoining edge where the back surface meets the outersheath, and wherein the polyurethane bonding material covers at least aportion of the adjoining edge and is in contact with the outer sheathand the back surface to bond at least a portion of the wire set to theovermolded portion following the overmolding process.
 8. The apparatusof claim 5, wherein the polyurethane bonding material is a piece ofpolyurethane film.
 9. The apparatus of claim 5, wherein the outer sheathand the overmolded portion are composed of polyvinylchloride.
 10. Theapparatus of claim 5, wherein the apparatus is a molded socket.
 11. Anelectrical apparatus, comprising: a wire set having an outer sheathsurrounding at least a portion of a plurality of wires; and anovermolded portion being formed via an overmolding process and having anouter surface, wherein the overmolded portion surrounds at least aportion of the wire set; polyurethane bonding material applied to theouter surface of the overmolded portion following the overmoldingprocess to patch an area of the overmolded portion.
 12. The apparatus ofclaim 11, wherein the outer surface of the overmolded portion issubstantially cylindrical in shape and the polyurethane bonding materialis a piece of polyurethane film positioned around the circumference ofthe overmolded portion along a segment of the outer surface.
 13. Theapparatus of claim 11, wherein the outer sheath and the overmoldedportion are composed of polyvinylchloride.